ROBERT WYATT'S career has meandered long and strange, like an underground driver. He's played alongside Hendrix, Mike Oldfield and Phil Manzanera, as well as avant-garde extremists such as Fred Frith, with whom he hilariously appeared on Top Of The Pops in the mid-Seventies, covering The Monkees' 'I'm A Believer'.

His latest album, Shleep, features both avant-jazz saxophonist Evan Parker and Paul Weller. He's covered songs by artists as diverse as Chic and Ivor Cutler. Working from jazz, through to the relatively mainstream rock of Soft Machine and Matching Mole, he was left permanently wheelchair-bound in the mid-Seventies after drunkenly falling out of a window several storeys high. Since then, he has forged a musical style all his own, one that combines plaintive drones and disingenuous, childlike repeated musical phrases with a vastly sophisticated exploratory sensibility. Wyatt's music reflects his character – mischievous, desolate, self-mocking, indignant, intimate and enigmatic, sensitive and resigned, open and vulnerable.

He was a communist – but that was somehow a manifestation of his extreme niceness rather than any ideological bloody-mindedness. It's genuinely affecting to hear him talk of the depression and nervous breakdowns that have dogged him in the Nineties, since his last album proper, 1991's bleak Dondestan.

"Maybe it's a total coincidence, but after Major got back in again in 1992, I didn't make a record under my own name the entire period he was in office," he reflects, sipping tea in a cafe near Great Ormond Street. "I didn't exactly go on strike, but..."

Now, however, he's had the "wind put back in his sails" with Shleep, his finest work in years, a genuinely collaborative effort involving, as well as Parker and Weller (a "hero" of Wyatt's who rockets in my estimation for his in-the-spirit contributions here), Eno, Phil Manzanera – who was generous with his studio facilities – and trombonist Annie Whitehead. It's reminiscent of 1975's Ruth Is Stranger Than Richard, recapturing, in Wyatt's own words, the "recklessness" of the intriguing underside of the prog-rock era. "I've bounced back now," he assures me. "Though always I have this feeling I'm on borrowed time..."

ROBERT WYATT has good and influential friends, but although his own music eclipses most of their efforts, he's never enjoyed similar levels of commercial success. "I've always fallen between tramlines," he laments. He's perceived as quintessentially English, having arisen from the so-called "Canterbury Scene" and having always sung in an open, unaffected Cockney accent years before Johnny Rotten. That, however, was out of a loathing of fake Seventies American accents. He is, in fact, a stern internationalist, who once said of himself in third person, "his political inclination is to be a traitor".

Is that why he joined the Communist Party?

"Yeah," he says, "go straight for the enemy!"

Was he dismayed by the collapse of the Soviet Union?

"No, not really," he sighs. "I've got used to backing losers, you know what I mean? If you've sat in free jazz gigs where the group outnumbers the audience, you're used to political meetings which are exactly the same. What was more important to me was, for instance, that it called the bluff of the apartheid government in South Africa whose excuse had been, 'We can't have democracy because the ANC are a front for the Russians.' My initial interest in the Communist Party was that it struck me as the only truly non-racist, internationalist organisation and I cannot apologise for having been associated with that."

Indeed, Robert Wyatt was among the first white "prog" artists to break way from the patronising attitudes towards black music.

"I was very shocked in 1968 when we went to Detroit and there was MC5 and I was saying to them how great it must be for them being down the road from all those great black groups and these white kids weren't interested in them because they wore suits and did dance routines. I thought, fucking hell, this is like South Africa."

This was a revelatory moment, but he considers himself to have been truly reborn when he began his relationship with his wife, the artist and sometime collaborator Alfreda Benge.

Contrary to popular misconception, his masterpiece, the truly essential Rock Bottom (1974), is not a lament for his accident but a euphoric hymn of praise to the beginnings of their relationship when he became, in his own, later, ironic phrase, a "born-again cretin". The album was mostly written by the time of his accident.

"I CONSIDER THAT the start of my real life. The butterfly. Everything before that was the pupa." A surprising image, under the circumstances, but Wyatt has never regarded his disability as a personal disaster or affliction, nor the source of his bouts of depression.

Maybe it's for that reason that he's never bothered overmuch with campaigning for the rights of disabled people. "It was actually strangely liberating, because it meant I had to go it alone. The things that have brought me down have never been so banal as a physical accident. Being in a wheelchair helped me to concentrate and simplify."

In fact, the source of his anxieties has been lack of funds over the years, preventing him from recording as often as he'd like to. He's had various wrangles regarding ownership of his back catalogue, which have only just now been resolved by Rykodisc. "There are good people in this business – Joe Boyd, Geoff Travis. But they're rare. You do get ripped off and there's no rock'n'roll ombudsman to prevent it. I'm not Sting.

"At my level, you notice when money goes missing. Money I need to record. I'm just so hopeless at everyday living. The only way I can get my pride back is if I function musically." Today, pride thoroughly restored, Wyatt and Alfreda live up in a shack in Spurn Point on the East Coast, a life of cosy, domestic desolation, fending off for the moment the omnipresent threat of depression, a place whose naturalistic ebb and flow is reflected in some of Shleep.

What do you do?

"I've started studying insects. The way flies work when they paralyse a caterpillar and lay their eggs on it, then live off the caterpillar but don't kill it until they're just about to hatch, then they move in and eat the brain, then they're done. I know a lot of people like that!"